The recent design diversification requires the freedom of the shape of moldings. However, conventional metal moldings are limited in point of the freedom of their shape. Accordingly, filler-reinforced thermoplastic resin is now investigated for a substitute for metal. However, conventional filler-reinforced thermoplastic resin could not satisfy the requirements needed for various applications, such as heat conductivity, electromagnetic wave shieldability and dimensional stability at high temperature, and its properties are now desired to be as similar as possible to the filler alone.
For obtaining a filler-rich composition, proposed is a method of kneading and extruding the constituent components through an extruder with the extruder head kept open (JP-A 8-1663).
In the method, however, since the die is taken of f during kneading, the inner pressure in the extruder barrel could not increase during kneading, and, as a result, thermoplastic resin could not well mix with filler, and the resulting composition could not be uniform and its characteristics may greatly fluctuate.
On the other hand, when filler alone is used to meet the needs as above, it does not bond to each other and only a brittle material could be obtained. When thermosetting resin is used, its moldability and productivity would not be good. When a large amount of filler is introduced into a filler-reinforced thermoplastic resin composition, it is limited in an ordinary melt-kneading process, and a filler-rich material that may have the necessary characteristics is difficult to obtain.
Given that situation, it could be advantageous to provide tablets capable of being processed in melt and capable of efficiently exhibiting the characteristics of the filler used therein, a method for producing them, and their moldings.